Memory slots and cards connectors pinouts

Computer memory usually refers to a form of semiconductor storage known as random-access memory, typically DRAM (Dynamic-RAM) but many times other forms of fast but temporary storage. Without a significant amount of memory, a computer would merely be able to perform fixed operations and immediately output the result. In practice, almost all computers use a variety of memory types, organized in a storage hierarchy around the CPU, as a trade-off between performance and cost.

Another significant type of computer memory module is a flash memory which is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for general storage and transfer of data between computers and other digital products. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid state storage is needed.

MultiMedia Card (MMC)The MultiMediaCard (MMC) is a flash memory memory card standard. It has been superseded by Secure Digital cards (SD card), but still in use because MMCs can be used in most devices that support SD cards.